Yakunin, Alexander (University of Toronto)

Purpose

New Golds Mesquite gold mine is experiencing significant cyanide consumption at its heap leach operation. As a result, the process cannot rely on a steady stream of unutilized cyanide that can be recycled to the heap for further gold recovery. Consequently, nearly all of the free cyanide required to sustain gold production must be purchased as a make-up requirement in the form of sodium cyanide, which is a significant annual expenditure for the company. A previous study, conducted by a commercial environmental laboratory, determined that microbes, or a group of microbes, present in the heap ore, or make-up process water, are responsible for enhancing the rate of consumption of cyanide. In this project, we will identify the microbes that are responsible for cyanide biodegradation at the heap leach site. A protocol to suppress biodegradation will also be developed and communicated to the company. A potential follow-on to this project will be the development of a technology to biologically treat cyanide contaminated tailings.